2. We will be creating a program that continually prompts the user for grades. It will print out a letter grade each time the user enters a number. The value must be within 1-100, or 999 to stop the program. Then, it will print out the average of all grades entered. 3. Declare an initialize count, total, and sentinel at 0, 0, and 999 respectively. Hint: remember that the sentinel is a constant and must be declared in uppercase. 4. Create the priming read by initializing the number variable from user input as a number between 1-100 or 999. 5. Validate the user input using a while loop. If the input is invalid, continually ask them to enter a new number until their input is valid. Hint: You will need to use a while loop, compound condition and order of operations. 6. Create a while loop that continually asks for a number while the number is not equal to the sentinel value. a. Increment the count by one and add the number to the total. b. Determine the letter grade using the table below then display the results. Hint: The last value can be the else clause since every other value after 68 will fall in this range. Letter Grade A B C D F Value Range Greater than Greater than Greater than Greater than Less than 68 or equal to 92 or equal to 84 or equal to 76 or equal to 68 Print Statement {number} is an A! {number} is a B. {number} is a C. {number} is a D. {number} is an F. c. Prompt the user for a new number the same as the priming read. d. Create a while loop that tests the user input the same as the test after the priming read. 7. After your while loop has finished, calculate the average by dividing the total by the count.